Oil-in-water and water-in-oil-in-water emulsions can occur in many industrial systems. For example, these emulsions are a problem in many energy extraction systems because the produced fluids contain oil and solids dispersed in the produced water and separation of the oil and solids from the water is needed to comply with the oil sales specifications and to provide acceptable specifications before the water can be disposed or re-used.
In particular, oil-in-water and water-in-oil-in-water emulsions can be problems in produced fluid (steam assisted gravity drainage (SAGD), steam flood, etc.) separation processes where the oil and solids in the produced fluid are separated from the produced water in the produced fluid.
For example, SAGD operations inject steam into geological formations to stimulate the production of bitumen or heavy hydrocarbon. Oil sands deposits in Alberta, Canada, represent an area where this process is extensively used. Pairs of horizontal wells are bored into the oil-containing formation. The upper well injects steam and the lower well, which is positioned below the steam injection line, continuously extracts a complex emulsion. That emulsion contains bitumen and water. The emulsion is broken; the bitumen is sent for upgrading/refining, while the produced water (separated from the emulsion) is treated and reused as feedwater for the steam generators.